OpenCV: how to force the image window to appear on top of other windows?

Using

cvShowImage

, one can easily show an image in OpenCV. However, how do you tell OpenCV to show the window on top of every other window?

I run a full screen OpenGL application while showing images. The first time the OpenCV window pops up on top of my application window, but if I click on the window of my application (i.e. give focus back to it), then I can't manage to have the OpenCV come back on top of the OpenGL window, even when destroying and recreating the window.

I thought of renaming the window each time, but is there another way to do it?